# putchar

From cppreference.com
< c‎ | io

Defined in header ``<stdio.h>`` |  |
int putchar( int ch ); |  |

Writes a character ch to stdout. Internally, the character is converted to unsigned char just before being written.

Equivalent to putc(ch, stdout).

### Parameters

ch | - | character to be written

### Return value

On success, returns the written character.

On failure, returns EOF and sets the error indicator (see ferror()) on stdout.

### Example

Shows `putchar` with error checking

Run this code

    #include <stdio.h>
    #include <stdlib.h>

    int main(void)
    {
        int ret_code = 0;
        for (char c = 'a'; (ret_code != EOF) && (c != 'z'); c++)
            ret_code = putchar(c);

        // Test whether EOF was reached.
        if (ret_code == EOF && ferror(stdout))
        {
            fprintf(stderr, "putchar() failed in file %s at line # %d\n",
                    __FILE__, __LINE__ - 6);
            perror("putchar()");
            exit(EXIT_FAILURE);
        }
        putchar('\n');

        // putchar return value is not equal to the argument
        int r = 0x1070;
        printf("\n0x%x\n", r);
        r = putchar(r);
        printf("\n0x%x\n", r);
    }

Output:

    abcdefghijklmnopqrstuvwxy

    0x1070
    p
    0x70

### References

- C23 standard (ISO/IEC 9899:2024):

  - 7.21.7.8 The putchar function (p: TBD)

- C17 standard (ISO/IEC 9899:2018):

  - 7.21.7.8 The putchar function (p: TBD)

- C11 standard (ISO/IEC 9899:2011):

  - 7.21.7.8 The putchar function (p: 333)

- C99 standard (ISO/IEC 9899:1999):

  - 7.19.7.9 The putchar function (p: 299)

- C89/C90 standard (ISO/IEC 9899:1990):

  - 4.9.7.9 The putchar function

### See also

fputcputc | writes a character to a file stream (function)
C++ documentation for putchar

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